A typical wireless communications system comprises a plurality of wireless communications devices exchanging data with each other. In some wireless communications systems, for example, infrastructure networks, the system may further comprise a wireless base station for managing communications between the wireless communications devices. In other words, each intra-system communication would be exchanged via the wireless base station. In other wireless communications systems, for example, mesh networks and ad hoc wireless networks, the wireless base station may be omitted, i.e. the wireless communications devices may communicate directly with each other.
The wireless communications devices may communicate with each other based upon a wireless communications protocol. The 3rd Generation Partnership Project Long Term Evolution (3GPP LTE) wireless communications protocol is a robust technology aimed at providing metropolitan area networks, as disclosed in the 3GPP TS 22.011 V8.9.0 (2009-09) Technical Specification, which is hereby incorporated by reference in its entirety. In particular, the LTE wireless protocol is commonly referred to as the fourth generation cellular protocol.
The LTE wireless communications protocol may provide for: increased bandwidth, low latency, and increased signal penetration. Moreover, the LTE wireless communications protocol provides an entirely packet switched protocol for both voice and data, and a simplified infrastructure that is easily integrated into legacy systems. In public safety applications, a municipality may provide an LTE wireless network for use by personnel, such as law enforcement and maintenance workers.
In some public safety applications, the communication system may need to support Push-to-Talk (PTT) features. Typically, when a user wishes to initiate a PTT call request in the communication system, the respective device sends a unicast PTT call request to the intended recipient. In some applications, it may be desirable to allow the PTT call request to be sent to multiple users, i.e. a multicast PTT call request.